This invention relates to nanoparticles. In particular, this invention relates to nanoparticles that are clinically applicable for diagnostic and/or therapeutic uses.
Medical imaging is used to collect information about a subject. In some types of imaging, a contrast agent is administered to the subject. The contrast agent selectively binds to a bioparticle or other structure of interest in the subject. This contrast agent is then detected using a medical imaging device and the collected information is used to develop an image or the like.
Although much information can be gathered from even a single medical image, multiple imaging techniques are necessary to provide comprehensive quantitative diagnostic information having high spatial and temporal resolution, high sensitivity of detection, and tomographic capability. In the past, this has often meant that multiple contrast agents would need to be administered to a single subject for each performed modality.
Multimodal contrast agents have been developed that are suitable for detection by various types of modalities. These multimodal contrast agents typically include multiple entities that are each detectable by a separate modality. The multiple entities are typically joined together using chemical linkers to make particles that each contain all of the respective multiple entities. However, the chemical linkers often have varying stabilities in cells and tissues or across time, meaning that some of the entities could separate, thus degrading the quality and usefulness of these contrast agents.
To avoid the problems of chemically linking multiple entities together, some have attempted to form contrast agents having a core-shell structure. However, to date, there have been significant problems developing a core-shell structure that can be clinically applied. The currently available particles either require the use of toxic chemicals during synthesis that limit the use of the resultant contrast agent in the human body or possess a morphology that prevents the particles from being effectively functionalized with targeting moieties.
Hence, a need exists for a multimodal contrast agent that is clinically applicable and efficiently functionalized.